INTEGRATED CONNECTIVE-TISSUE IN BIOABSORBABLE BARRIER MATERIAL AND PERIODONTAL REGENERATION

THE OBJECTIVE OF THIS STUDY was to evaluate the relationship between i ntegrated connective tissue (ICT), that is, the presence of connective tissue into the membrane structure, and the clinical outcome of membr ane-supported periodontal surgery. Twenty-six systemically healthy sub jects affected by chronic adult periodontitis were enrolled in the stu dy. One tooth site per patient, associated with an angular bony defect and an attachment loss of > 7 mm, was selected to be treated by means of a guided tissue regeneration procedure using a bioabsorbable membr ane, Barrier material was surgically removed after 4 weeks for SEM ana lysis, For each treated site, the difference in clinical attachment lo ss, probing depth, and gingival recession between the baseline examina tion and follow-up 6 months after the second surgery was calculated. G ain of attachment was statistically (P < 0.001) greater in sites with no membrane exposure when compared to sites with exposed barrier mater ial (5.5 +/- 1.0 vs. 4.0 +/- 0.6), while further gingival recession wa s greater (3.0 +/- 0.9 vs. 2.1 +/- 0.5) in sites with clinically expos ed membranes. The results of SEM analysis revealed that when connectiv e tissue structures were observed on membrane surfaces, no bacteria co uld be detected; conversely, areas heavily colonized by bacteria did n ot show the presence of connective tissue. Regression analysis indicat ed that integrated connective tissue on the external layer of the barr ier material was positively correlated with the amount of attachment g ain and negatively with the amount of gingival recession. Bacterial co lonization of the membrane was negatively correlated with attachment g ain and positively with gingival recession. It was concluded that conn ective tissue integration is an important biological phenomenon in pre venting membrane exposure and bacterial plaque colonization and thus i n enhancing the clinical outcome following guided tissue regeneration surgery. surgery.